Minimum Bactericidal Concentration (MBC) of Extract from Pouzolzia Zeylanica against Respiratory Bacteria from Pigs and Chickens

Abstract

This study aimed to determine the minimum bactericidal concentration (MBC) of the aqueous extract from Pouzolzia zeylanica to 20 bacteria isolates from the respiratory tract of swine and chicken including Pasteurella multocida, Bordetella bronchiseptica, Actinobacillus pleuropneumoniae, Ornithobacterium rhinotracheale (ORT) by agar dilution method. Results showed that that the minimum bactericidal concentration (MBC) for A. pleuropneumoniae, B. bronchiseptica, P. multocida and ORT is 250 - 500 mg/ml, 250 - 500 mg/ml; 500 - 1000 mg/ml; and 500 - 1000 mg/ml, respectively. Thus, the aqueous extract of Pouzolzia zeylanica has the best effect on killing A. pleuropneumoniae, B. bronchiseptica and killing P. multocida and Ornithobacterium rhinotracheale at higher concentrations. The MBC values of control antibiotics including gentamicin were 4 - 8 µg/ml; 8 - 32 µg/ml; 0.25 - 0.5 µg/ml; 8 – 16 µg/ml for the above 4 bacteria, respectively. MBC of tetracycline is 16 - 32 µg/ml, 64 - 128 µg/ml; 64 - 128 µg/ml; 16 – 64 µg/ml for A. pleuropneumoniae, B. bronchiseptica, P. multocida, and Ornithobacterium rhinotracheale, respectively. The aqueous extract from Pouzolzia zeylanica can also kill resistant isolates of these four mentioned bacteria species.